Process all the cookies, except for about 6-8 in a food processor until finely ground. Add butter; mix well. Press onto bottom of a 13x9-inch pan. Clean out food processor to use for filling.

In food processor, mix cream cheese until smooth. Add sugar and vanilla and mix until well blended. Add sour cream; mix well. Add eggs, 1 at a time, mixing just a little after each egg. Pour half of the batter onto the crust. Pour remaining batter into a medium size bowl.

Pour melted chocolate into remaining batter; and mix well with a wire whisk. Pour over white batter.

Chop remaining cookies; sprinkle over batter.

Bake at 325 degrees for 45 minutes, or until center is almost set. Cool completely, then refrigerate at least 4 hours before cutting into squares.